The invention relates generally to devices and methods for delivering moisture and/or other substances to the nasal passages concurrent with oxygen delivery using a nasal cannula, and more specifically to devices and methods for clipping or otherwise attaching a moisture saturation device onto a conventional nasal cannula.
A conventional nasal cannula 10 (FIG. 1) is a device used to deliver supplemental oxygen, air or other breathing gas mixture to a patient with respiratory, cardiac or hematologic disease. A conventional nasal cannula consists of a lightweight breathing tube 11 having two prongs 12 at one end. The two prongs are placed in the patient's nostrils to deliver the breathing gas. The other end of the tube is connected to a breathing gas supply, such as an oxygen tank or a wall connection in a hospital, via a flowmeter. The cannula may be attached to the patient by hooking the tube over the patient's ears. Typical adult nasal cannulas carry 1-5 liters of oxygen per minute while wider bore humidified nasal cannulas carry up to 60 liters of air/oxygen per minute. The nasal prongs typically contact the delicate mucosa of the nasal septum and turbinates, leading to ulceration
The oxygen or air flowing from the gas source to the patient is usually very dry and can cause excessive drying of the mucosal membranes, discomfort, and in some cases ulceration of the nasal passage. Ulceration of the delicate nasal mucosa can cause nosebleed, or epistaxis which is especially serious in elderly patients who intentionally or unintentionally take medications or herbal supplements that thin their blood and impair normal blood clotting (aspirin, warfarin, apixaban eliquis, dabigatran etexilate pradaxa, edoxaban savaysa, rivaroxaban xarelto, fish oil, vitamin E, ginkgo, garlic capsules and others). Nasal ulcerations and bleeding in these patients can lead to respiratory problems, anemia and pain.
To address the problem of excessive nasal drying, it is common to pass the breathing gas through a chamber containing water or other fluid to increase the moisture content of the gas prior to delivery to the patient. However, such devices are often only minimally effective and do not prevent the direct abrasive effects of the nasal prongs irritating the delicate nasal mucosa.
U.S. Pat. No. 6,354,293 describes another approach to address the problem of dry nasal membranes. A humidifying element is placed retained under the user's nose, and oxygen or other gas is passed through the breathing humidifier into the users nostrils. The humidifying element is held between the nasal cannula and the nose, but is easily dislodged and can be dropped or lost, particularly with ambulatory patients.
For these reasons, it would be desirable to provide a nasal air humidifying device which can be clipped or otherwise removably attached to a conventional nasal cannulas to enhance humidification of the breathing gas and avoid direct abrasion of the delicate nasal mucosa by the nasal prongs of supplemental oxygen.